Open-hole anchor whipstock system

ABSTRACT

The various embodiments of the present invention provide an open-hole anchor whip stock system. The open-hole anchor whip stock system includes an anchor, a whip face attached to the anchor, a drilling assembly attached to the whip face. The anchor is set at an optimal depth in a formation drilled by exerting a force which in turn activates a mechanism causing an expansion and fixation of the anchor on the formation of a surface and the drilling assembly slides over the surface at an angle defined by the whip stock so as to cut through the formation thereby forming a directional path hole. The whip face is a solid shaft provided with a 3° ramp along the longitudinal axis of rotation the shaft which induces a deflection on the drilling assembly thereby reducing bending stress on the drilling assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority benefit of U.S. provisional application No. 61/358,908, filed Jun. 27, 2010, which is incorporated herein by reference in its entirety.

SPONSORSHIP STATEMENT

The present invention is sponsored by Iranian National Science Foundation.

BACKGROUND

1. Technical field

The embodiments herein generally relate to a drilling systems and methods and particularly relate to an open-hole anchor whip stock system. The embodiments herein more particularly relates to a mechanical expandable open-hole anchor whip stock system for drilling surfaces with accurate control of depth and direction of the drill.

2. Description of the Related Art

In the existing techniques, the drilling operations often encounter numerous problems such as backing off, getting stuck or breakage of drill string of tools within the well and so on. During such circumstances, the drilling operation is carried out by filling the well up to a small depth above the unwanted object with cement. After the cement is hardened, two or three joints of drill pipe placed above a drilling bit and required drill collar joints arranged above the drill pipes are used to drill the well. However this operation consumes a large amount of time. Also, this technique cannot suffice the requirement in case of problems like formation of discontinuous cement bond, bad cement quality, loss of cement from the formation fractures, contact with hard formations while drilling etc.

Further the existing drills experiences pressure loss during the process of drilling and also there are chances of blockage of wells due to movements of different land layers and the expected efficiency of drilling is not achieved. Also, multiple attempts may be frequently required when a blockage is encountered in the drilling surface, which is a time consuming, expensive and tedious process and also necessitates reconfiguration of the drilling.

The process of cementing, grouting and drying cement according to the current methodology requires more time which in turn increases the overall expense of drilling. Further, the terminals of the well is cemented to a distance and the cemented surface is drilled after a time break in which cement is supposed to reach the required stability, which results in instability of the top layer formed for drilling the well. Furthermore, the process of cementing causes the cement to be mixed with mud, which in turn reduces the strength of the top layer.

Hence there is a need to provide an open-hole anchor whipstock system which provides for accurate control of kickoff depth and direction of drilling. Further there is also a need for an open-hole anchor whipstock system to drill continuously for creating an opening window for the drilling trajectory. Moreover there is a need for an open-hole anchor whipstock system which lowers the directional drilling time and increase the accuracy of the drilling.

The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.

OBJECTS OF THE EMBODIMENTS

The primary object of the embodiments herein is to provide an open hole anchor whipstock system for drilling continuously by creating a passage channel for the drilling trajectory.

Another object of the embodiments herein is to provide an open-hole anchor whipstock system that provides accurate control of the kick-off depth and the direction of drilling.

Yet another object of the embodiments herein is to provide an open-hole anchor whipstock system to increase the operational reliability in accordance with drilling.

Yet another object of the embodiments herein is to provide an open-hole anchor whipstock system with an anchor slip design to avoid bull heading of the cement.

Yet another object of the embodiments herein is to provide an open-hole anchor whipstock system to reduce the directional drilling time.

Yet another object of the embodiments herein is to provide an open-hole anchor whipstock system for sidetracking through formations with various hardness.

Yet another object of the embodiments herein is to provide an open-hole anchor whipstock system for drilling through formations with landing laterals.

Yet another object of the embodiments herein is to provide an open-hole anchor whipstock system which does not require reconfiguration of the drilling trajectory.

Yet another object of the embodiments herein is to provide an open hole anchor whipstock system, which reduces the rig time, involved for the cement plug to cure.

Yet another object of the embodiments herein is to provide an open hole anchor whipstock system with an increased axial and torsion load capacity.

These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

SUMMARY

The embodiments herein provide an open-hole anchor whipstock system for drilling. The open-hole anchor whip stock system includes an anchor, a whip face attached to the anchor, a drilling assembly attached to the whip face. The anchor is set at an optimal depth in a formation drilled by exerting a force which in turn activates a mechanism causing an expansion and fixation of the anchor on the formation of a surface. Further the drilling assembly slides over the surface at an angle defined by the whip stock so as to cut through the formation thereby forming a directional path hole.

According to an embodiment herein, the whip face is a solid shaft which is cut at a concave angle along a longitudinal axis of the shaft.

According to an embodiment herein, the cut on the whip face induces a 3° angular deflection on the drilling assembly which in turn reduces the bending stress on the drilling assembly.

According to an embodiment herein, the anchor is a cylindrical expandable tool including one or more fixed parts and movable parts.

According to an embodiment herein, the one or more movable parts include a plurality of blades.

According to an embodiment herein, the plurality of anchor blades are tri-axial metal slips adapted to expand into the formation towards a downward direction of the hole when a mechanical pressure is exerted on the plurality of anchor blades.

According to an embodiment herein, the drilling assembly includes a plurality of milling bits to cut through the formation.

According to an embodiment herein, the plurality of milling bits is made of Tungsten-Carbide stripes.

According to an embodiment herein, the whip face guides a metal casing to a casing pipe fixed in the hole drilled.

According to an embodiment herein, the rotational movement of the drilling assembly causes a downward movement of the casing pipes until a desired depth is reached.

According to an embodiment herein, the whip face is attached to the top of the anchor through a bolt mechanism.

According to an embodiment herein, the milling assembly is attached to the top of the whip face through a screw fastener.

According to an embodiment herein, the drilling assembly further comprises a hinge connector plus upper cone, an upper sleeve, a mandrel extension, a rachet ring, a stop ring, a lower cone plus setting collar, a lower sleeve, a bottom cap, a guide blade, one or more upper slips, one or more lower slips, an extension cementing tail, a socket head cap screw, a lower cone shear screw and an upper cone shear screw.

According to an embodiment herein, the drilling assembly controls the depth and the direction of the hole using the drilling assembly.

According to an embodiment herein, the whip face transmits the torque required for rotation of the drilling assembly during tripping.

According to an embodiment herein, the whip stock is operated in parallel with the mechanical expandable anchor during setting an optimal depth for drilling by exposing weight.

According to an embodiment herein, the drilling assembly eliminates the uncertainty of kicking off with the cement plug.

These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

FIG. 1 illustrates a perspective view of an open-hole anchor whipstock system, according to an embodiment of the present disclosure.

FIG. 2 illustrates an exploded view of the open-hole anchor whipstock system, according to an embodiment of the present disclosure.

FIG. 3 is a graph illustrating the operation time comparison between the open-hole anchor whipstock system with a cement plug sidetracking system, according to an embodiment of the present disclosure.

Although the specific features of the embodiments herein are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the embodiment herein.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

The embodiments herein provide an open-hole anchor whipstock system for performing faster and higher-quality sidetracking with maximum probability of success on the first attempt and considerable saving in rig time. The open-hole anchor system also provides accurate control of the kickoff depth and the direction of drilling. The open-hole anchor whipstock system is adapted to drill through medium and hard surfaces with tight True Vertical Depth (TVD) tolerance.

The open-hole anchor whipstock system includes a whip face, an anchor and a drilling assembly attached to the whip face. The anchor is set at an optimal depth in a formation drilled by exerting a force which in turn activates a mechanism causing an expansion and fixation of the anchor on the formation of a surface. Further the drilling assembly slides over the surface at an angle defined by the whip stock so as to cut through the formation thereby forming a directional path hole.

The whip face is a solid shaft which is cut at a concave angle along a longitudinal axis of the shaft. The concave angle induces a 3° angular deflection on the drilling assembly which in turn reduces bending stress on the drilling assembly.

The anchor is a cylindrical expandable tool comprising one or more fixed parts and movable parts where the one or more movable parts include a plurality of blades where the plurality of anchor blades are tri-axial metal slips adapted to expand into the formation towards a downward direction of the hole.

The drilling assembly includes a plurality of milling bits to cut through the formation and plurality of milling bits is made of Tungsten-Carbide stripes.

The whip face guides a metal casing to a casing pipe fixed in the hole drilled. The whip face is attached to the top of the anchor through a bolt mechanism.

The rotational movement of the drilling assembly causes a downward movement of the casing pipes until a desired depth is reached. The drilling assembly is attached to the top of the whip face through a screw fastener.

FIG. 1 illustrates a perspective view of an open-hole anchor whipstock system, according to an embodiment of the present disclosure. With respect to FIG. 1, the open-hole anchor whipstock system 100 includes a whip face 102, an anchor 104, and a milling assembly 106. The drilling assembly 106 is attached to the whip face 102. The whip face 102 is a solid shaft which is cut at a concave angle of 3° along the length of the shaft in conjunction with the longitudinal axis of rotation. The anchor 104 is a cylindrical tool made up of fixed and movable parts. The movable parts of the anchor 104 include a plurality of blades that are free at one end to expand into formation. The drilling assembly 106 includes an arrangement of a plurality of milling bits for milling both metal and formation. The plurality of milling bits includes three hard bodies dressed with tungsten-carbide stripes.

The whip stock 102 is attached to the top of the anchor 104 through a bolt mechanism and the mill assembly 106 is attached to the top of the whip stock 102 with a screw mechanism. The open-hole anchor whipstock system 100 is then sent to target depth into the hole. After the bottom of anchor 104 sits on the well bed, a compressive force is exerted on a string which activates a mechanism ending in the expansion then fixation of anchor blades into the formation. When an additional weight is exerted, the screw mechanism connecting the drilling assembly with the whip face shears away and the drilling assembly 106 slides over the concaved surface in the azimuth angle determined by the whipface 102. The open-hole anchor whipstock system 100 remains in the surface and is not moved downwards as the anchor blades gets attached to the walls of the well and the milling bits cut through the formation until a directional hole is formed.

FIG. 2 illustrates an exploded view of the open-hole anchor whipstock system, according to an embodiment of the present disclosure. With respect to FIG. 2, the open-hole anchor whipstock system 100 includes an anchor 104, a whip face 102 attached to the anchor 104 and a drilling assembly 106. The drilling assembly 106 includes a plurality of milling bits made of tungsten carbide stripes or any other suitable material. The drilling assembly further includes a hinge connector plus upper cone 1, an upper sleeve 2, a mandrel extension 3, a rachet ring 4, a stop ring 5, a lower cone plus setting collar 6, a lower sleeve 7, a bottom cap 8, a guide blade 9, one or more upper slips 10, one or more lower slips 11, an extension cementing tail 12, a socket head cap screw 13, a lower cone shear screw 14, and an upper cone shear screw 15.

The whipface 102 transmits the torque required for rotation of the drilling assembly 106 during tripping. The whipface 102 acts as a deflector to deflect the direction of the drilling assembly 106 in the drilled hole. The deflection is provided by the 3° ramp of the whipface 102 which in turn reduces the bending stresses of the drilling assembly 106. The whipface 102 is operated in parallel with the mechanical expandable anchor 104 for setting an optimal depth by exposing weight on the anchor.

The open-hole anchor whipstock system 100 is used for creating opening window in drilling wells with a Case Hole. The anchor 104 is operated through at least one of a hydraulic actuation method and mechanical actuation method and is locked to a metal casing, such as a steel casing, installed in the well. The whipface 102 installed on the anchor 104 shreds the drilling assembly 106 for boring the drill from the system and guides the drilling assembly 106 towards the casing pipe that is assumed as a main element in opening window. After setting anchor 102 in the well by applying a determinate weight, the bolt mechanism placed between drilling assembly 106 and whipface 102 is cut and drilling assembly 106 is released. The rotation of the whipface 102 causes the rotation of the drilling assembly 106 in a downward direction thereby causing the opening window to extend as a passage channel.

The anchor 104 can be locked at the bottom of the well by one time run and the operation can be started simultaneously. The open-hole anchor whipstock system is used for side tracking by creating an opening window and performing diverges drilling with the special drilling assembly 106. The anchor blades are closed with chains of whipface 102 and the drilling assembly 106 which are then set into the well. The end point which is called heel of tail, lies into the end of well. The anchor blades get opened when a mechanical force is applied through the chains of the whipface 105 and the drilling assembly 106. The anchor blades move in a radial direction in the well and the anchor blade is pressed to the wall of the well so as to fix the anchor 104 at that point. The anchor 104 is designed in such a way that it does not allow the movement of the blades once it is set. By increasing the pressure on the anchor blades, the anchor blades become more open and the gets adjusted more to the well. At the time of digging, special digging-pipes are formed a stand in 3 branches state and will bectied to each other besides digging platform, each stand has 36 m length and the digging requires 3600 m and 100 branches.

The open-hole anchor whipstock system 100 is used in oil-wells which are not equipped by pipes and the wall of well is constituted by stone, sand, chalk or caleareous layer, so the possibility of destruction is less. The anchor 102 will be locked at the bottom at well and makes this possibility to lock the system at the bottom of the well. After reaching the well, the anchor sticks to the bottom of the well, by using some pins weight like fuses it will be cut and anchor blades will expand more on the grade surface.

The open-hole anchor packer is made in different diameters after patting on the bottom of open oil-wells by increasing weight this diameter increases and will be locked to the wall of the well. All the other systems which will be locked in the well by bearing a weight, besides plastic cover or elastic (rubber) or composite or other kinds of steel alloy or colored metals are accounted as this kind.

FIG. 3 is a graph illustrating the operation time comparison between the open-hole anchor whipstock system with a cement plug sidetracking system, according to an embodiment of the present disclosure. With respect to FIG. 3, the graph 300 indicates that the open-hole anchor whipstock system consumes less time for drilling as compared with the conventional cement plug systems. The open-hole anchor whipstock system is adapted to drill through medium to hard formations.

The various embodiments of the present disclosure provide an open-hole anchor whipstock system for drilling continuously by opening a window for the trajectory. The open-hole anchor whipstock system drills faster with maximum probability of success on the first attempt and considerable savings in rig time. The open-hole anchor whipstock system provides accurate control of kickoff depth and direction and increases operational reliability which in turn results in saving time. The open-hole anchor whipstock system considerably lowers directional drilling time and increases the dependability of operation. The open-hole anchor whipstock system eliminates the possibility of reconfiguration of the drilling trajectory. The open-hole anchor whipstock system does not require any cementation thereby saving cost and time.

The foregoing description of the specific embodiments herein will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments herein without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.

Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications. However, all such modifications are deemed to be within the scope of the claims.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between. 

1. An open-hole anchor whipstock system comprising: an anchor; a whip face attached to the anchor; and a drilling assembly attached to the whip face; wherein the anchor is set at an optimal depth in a formation drilled by exerting a force which in turn activates a mechanism causing an expansion and fixation of the anchor on the formation of a surface and the drilling assembly slides over the surface at an angle defined by the whip stock so as to cut through the formation thereby forming a directional path hole.
 2. The open-hole anchor whipstock system of claim 1, wherein the whip face is a solid shaft which is cut at a concave angle along a longitudinal axis of the shaft.
 3. The open hole anchor whipstock system of claim 2, wherein the cut on the whip face induces an 3° angular deflection on the drilling assembly thereby reducing bending stress on the drilling assembly.
 4. The open-hole anchor whipstock system of claim 1, wherein the anchor is a cylindrical expandable tool comprising of one or more fixed parts and movable parts.
 5. The open-hole anchor whipstock system of claim 4, wherein the one or more movable parts includes a plurality of blades.
 6. The open-hole anchor whipstock system according to claim 4, wherein the plurality of anchor blades are tri-axial metal slips adapted to expand into the formation towards a downward direction of the hole.
 7. The open hole anchor whipstock system of claim 1, wherein the drilling assembly comprises a plurality of milling bits to cut through the formation.
 8. The open hole anchor whipstock system of claim 6, wherein the plurality of milling bits is made of Tungsten-Carbide stripes.
 9. The open hole anchor whipstock system according to claim 5, wherein the whip face guides a metal casing to a casing pipe fixed in the hole drilled.
 10. The open hole anchor whipstock system according to claim 8, wherein a rotational movement of the drilling assembly causes a downward movement of the casing pipes until a desired depth is reached.
 11. The open-hole anchor whipstock system of claim 1, wherein the whipface is attached to the top of the anchor through a bolt mechanism.
 12. The open-hole anchor whipstock system of claim 1, wherein the milling assembly is attached to the top of the whipface through a screw fastener.
 13. The open hole anchor whipstock system according to claim 1, wherein the drilling assembly further comprises: a hinge connector plus upper cone; an upper sleeve; a mandrel extension; a rachet ring; a stop ring; a lower cone plus setting collar; a lower sleeve; a bottom cap; a guide blade; one or more upper slips; one or more lower slips; an extension cementing tail; a socket head cap screw; a lower cone shear screw; and an upper cone shear screw. 